Comprehensive backbilling limits list

We built a great state-by-state list over in the Statute of Limitations topic, but that focused on how far back WE can claim refunds. This thread is the flip side: how far back can the UTILITY backbill the customer if they discover an underbilling? This matters because when we find a metering error that was undercharging the client, we need to know the utility's backbilling exposure.

My list so far:
Ohio: 12 months (PUCO rule)
Georgia: 24 months (PSC rule)
New York: 24 months (PSC opinion, but varies)
Pennsylvania: 4 years (PUC regulation)
California: 3 years for non-residential (CPUC)
Texas: 180 days (PUC Subst. Rule 25.126)

Adding:
New Jersey: 6 months (BPU informal policy)
Virginia: 12 months (SCC regulation)
Florida: 12 months (PSC rule)
North Carolina: 12 months (NCUC)
South Carolina: 12 months (PSC rule)
Tennessee: varies by distributor (no statewide rule for TVA territory)

Texas at 180 days is by far the most customer-friendly. If a utility discovers they've been underbilling a Texas customer, they can only backbill 6 months regardless of how long the error has been in place.

This is critical information for every auditor. When you find a metering error that's been undercharging the client, the first thing you need to assess is the backbilling exposure. If the client is in Texas with a 180-day backbilling limit, the exposure is minimal. If they're in Pennsylvania with a 4-year limit, the exposure could be enormous. This risk assessment helps the client make an informed decision about whether to proactively report the error or wait for the utility to discover it — keeping in mind the ethical obligations we discussed in the Ethics topic.

Saving this thread right next to the refund limits thread. These two lists together cover both sides of the equation. Essential reference material.